timesDown = 0

function comeup()
        for i=1,timesDown
        do
        turtle.digUp()
        turtle.up()
        end
end

function bedrockcheck()
        if not turtle.digDown() then
        comeup()
        break
        end
end

function godown()
        while turtle.detectDown() do
        turtle.digDown()
        turtle.down()
	timesDown = timesDown+1
        end
end

function cavefind()
    while not turtle.detectDown() do
    comeup()
    end
end

godown()
cavefind()
bedrockcheck()
comeup()